Control system for fuel burners



Dec.' 8, 1931. R 1 EISEMAN 1,835,028

5 'CONTROL SYSTEM `FOR FUEL BURNERS Filed Nov. 11, 1927 a as Rig v 'y Gaz/67222# may? Patented Dec. 8, 1931 UNITED STATES PATENT OFFICE ROBERT J. EISEMAN, OF CLEVELAND, OHIO,- ASSIGNOB '10 THE K-W IGNITION OOR- PORATION, F CLEVELAND, OHIO CONTROL SYSTEM FOR FUEL BURNERS Application inea Novemnei 11, 1927. serial No. 232,577.

This invention relates to improvements in controlsystems for fuel burners, including t-he control of the electric igniter as well as the fuel feed to the combustion cha1n 5 ber in which the igniter is located. It has special utility in connection with oil burners.

While the invention may have other applications where controls of one kind or another may be advantageously employed in connection with the operation of a transformer, the specific use mentioned above is the one which the invention is primarily intended.

The electrical energy for igniters of this type is usually derived from a 110V voltvlighting circuit, and in order to hold down the current, both by ohmic and inductive resistance,l the number of turns in the primary is ordinarily greater than would be required merely for the production of the necessary magnetic flux. When this practice is followed, the number of turns in the secondary must be increased also, and as the proportion of secondary to primary turns for this class of work is 'about 100 to 1, it is evident that any increase of turns in the primary over what is absolutely necessary is a costly matter( Furthermore, it is desirable to employ as few turns as possible on account of the heat resulting from the copper loss.v

One of the objects of the present invention is the provision of a system which will choke down the primary current going to the transformer byA means exterior to the transformer, thus permitting the use of a transformer with relatively few turns in the primary and a correspondingly reduced number of turns in the secondary, without a wasteful use of energy. v

Another object is the provision of mean .for enabling the said choking means to do other useful work.

A further obj ect is the provision of a magnetic control for a fluid valve or other moving part, in which control there is embodied the choking means above referred to.

A further object is the provision of means for producing inthe igniter a fat spark at the beginning of its operation and before the fuel reaches the combustion chamber, whereby any soot upon the points of the igniter willbe burned off.

Another object is the provision of means for opening a valve without the expenditure of any considerable amount of electrical ener-gy for that purpose alone, particularly a valve that is positively closed as by a spring or weight.

Other objects and features of novelty will appear as I proceed with the description of that embodimentl of the invention which, for the purposes of the present application, I have illustrated in the accompanying draw ing, in which:

The single ligure is a diagrammatic illustration of an electric system for controlling the flow of fuel to a combustion chamber and for igniting the same in said chamber.

In the drawing, alternating current supply line wires are indicated at 10 and 11. A 70 transformer core of ordinary shape and construction is shown at 12. The secondary coil 13 of the transformer is connected by wires 14; and 15 with the sparking points 16 and 17 of an igniter such as may be employed in the combustion chamber of an oil burner or gas burner, or the like.

The primary coil 18 on the other leg of the core 12 is connected at one end by a conductor 19 with line wire 10, a switch 9 being in this instance interposed between the ends of conductor 19. This switch maybe manually controlled or it may be automatically operated in connnection with burner mechanism not herein disclosed. The opposite end of the coil 19 is connected with one extremity of a winding 20 on one leg of a U-shaped core 7 of an electromagnet 8, the other end of the winding 20 being connected by a conductor 21 with the line wire 11. The two coils 18 and 20 are thlis connected in series across the line wires 10 and 11. On the other leg of the core 7 there is a high-resistance Winding 22 which is connected in multiple with a motor 23 by conductors 24 and 25, the motor being connected across the line wires 10 and 11 byY conductors 26 and 27 respectively, the conductor 26 including a switch 28, either manualor automatic. The motor 23 may be used to drive a blower for use in connecline.

"tion with the fuel burning apparatus, such as Amagnet. Adjacent the armature 29 there is a casting 30 having a lower chamber 31 with which is connected a pipe 32. of a fuel line and an upper chamber 33 with which is connected another pipe 34 of the fuel The chambers '31 and 33 are separated by a dividing wall 35 throughwhich there is a passage 36 that is closed by a valve 38 operatively .connected with the armature 29, these two parts being preferably directly connected by means of a stein 38. Thecoil spring 39 surrounding the stein 38 tends to maintain the valve 37 closed and to hold the armature 29 in its lowermost or unattracted position.

In the operationvof the system as applied to a fuel burner, the switches 9 and 28 are closed eitherA simultaneously or otherwise. Current then flows through the coils18 and 20, the latter coil functioning as achoke but its choking eectbeing limited on account of the breaks in the metal path for the magnetic flux. The current through the coil 18 is, therefore, highest atV that time, which isadvantageous in that the proportionatelyy high current-in the secondary coil of the transformer produces an especially fat spark across the terminals 16 and 17 so as to burn 0H any soot deposited upon the latter preparatory to the admission of fuel `to the burner. This effect, of course, is only momentary, being terminated as soon as the armature29 rises against the act-ion of spring 29 in response to the energization of the` electromagnet 8 by means of the current flowing vin coil-20. As soon as the metal path for the magnetic flux of electromagnet 8 is completed by the armature 29 bridging the ends of the core 7, the full choking effect of coil 20 is attained and the intensity of the sparks across points 16 and 17 is somewhat reduced.A The choking effect in coil 20 of course serves to reduce the current flow in coil 18, Aand thereby permits a reduction inthe number of turns in both the primary and secondary coils 18 and 13- of the transformer. At the same time, however, the energy expended in the choking coil is not per mitted tovbe wasted, but is utilized to do luseful work.

y The coil 22, which is formed of relatively high-resistance wire, draws insuflicientscurthat if. the igniter fails to operate, for any reason, as, for instance, because of a broken circuit or a short circuit, so that there is no load upon the secondary of the transformer, the current traversing the primary coil 18 and also the winding 20 of the electromagnet is too small to raise the armature 29 against the action of spring 39. Hence, when there is no spark in the igniter there is no fuel feed to the burner, a protective measure of con-l siderable importance. I

While in the preceding disclosure I have mentioned and illustrated a valve for a fuel line as the control part operatively connected with the armature 29, I do not desire lto s0 limit the invention, as controls of a different nature may be substituted for the valve without departing from the spirit of the invention.

Having thus described my invention, I claim:

1. In combination, a transformer of an igniter, and an electromagnet including a core, the primary coil ofthe transformer and the coil of the electromagnet being arranged ih series, whereby the electromagnet coil serves i as a choke for the primary coil of the transformer, said'electromagnet having an armature movable by the energization of the magnet coil, and adapted to cooperate with said ioocore to provide a closed metallic field f or the electromagnet.

2. In fuel burning apparatus, the comb-ination of a'transforrner, and an electromagnet including a core, coil and armature, the primary coil of the transformer and the coil of 110 'the electromagnet being arranged in series,

core and armature, a movable control member '120 operatively connected with said armature, theprimary coilvof the transformer and the coil 'of the/electromagnet beingbconnected in series, whereby the electromagnet serves both to actuate said control member and to/choke 1`25 the current through said primary coil.

4. In fuel burning apparatus, the combination of a transformer for the igniter thereof, a fuel valve, and an electromagnet having an armature4 operatively connected with said 130 A valve and having a coil connected in series with the primary of the transformer.

5. In combination, a transformer adapted to furnish high voltage current to an igniter for a combustion chamber, a valve adapted to control the flow of fuel to said chamber, an electromagnet` having an armature operatively Connected with said valve, the primary coil of the transformer and the coil of electro` magnet being connected together in series. i

whereby said electromagnet serves to open said valve and to choke the current flowing in said primary coil.

6. In a system of the character described, a transformer adapted to furnish high voltage current to an igniter for a combustion chamber, a valve adapted to control the iow of fuel to said chamber, an electromagnet having a winding, and an armature operatively connected with said valve, the primary coil of the transformer and the said winding of the electromagnet being connected together in series, a motor, and a holding coil on said electromagnet in multiple with said motor, whereby said armature when once attracted is held in that position and the said valve maintained open during the operation of the motor regardless of the electrical condition of the first-named winding.

7. In a system o f the character described, a valve adapted to control the flow of fuel to a combustion chamber, means tending to ,holdsaid valve in closed position, an electromagnet, an armature therefor operatively connected with said valve to open the same when signature.

ROBERT J. EISEMAN.

the armature is attracted by the magnet, a

transformer adapted to furnish high voltage current to an igniter for said combustion chamber, conductors for supplying current to the low tension side of said transformer and to said electromagnet, a common control therefor, a motor, and a holding coil on said electromagnet in multiple with said motor, whereby said armature when once attracted is held in that position and the valve maintained open during the operation of the motor re gardless of the electrical condition of said first-named Winding.

8. In a system of the character described, a transformer adapted to furnish high voltage current to an igniter, a valve adapted to control the flow of fuel, an electromagnet naving a winding and having an armature operatively connected with said valve, the primary coil of the transformer and the said winding of the electromagnet being connected in the same circuit, whereby an especially fat spark is produced in said igniter when the said circuit is first closed and a somewhat leaner spark after the valve is opened.

9. In a systemof the character described, a transformer adapted to operate anV igniter for a fuel burner, a valve for controlling the flow of fuel to said burner, an electromagnetic means for controlling said valve, said means 

